Spatially correlated x-ray and ultrasound mammographic imaging systems and method

ABSTRACT

The present invention provides for x-ray imaging and ultrasound imaging of a body region of interest in a spatially correlatable manner. The resultant x-ray and ultrasound images may be combinatively employed to provide three-dimensional information regarding a location of interest within the body, and is particularly apt for use in the analysis/biopsy of potential lesions and suspicious masses in a female breast. The invention provides for direct body contact by an ultrasound imaging head, as well as targeted ultrasound imaging of a selected portion of the region from which x-ray images are obtained. A user interface system facilitates various procedures including ultrasound guided needle biopsy procedures.

RELATED APPLICATION INFORMATION

This application is a divisional of U.S. patent application Ser. No.09/449,267, filed Nov. 24, 1999, now U.S. Pat. No. 6,459,925, issuedOct. 1, 2002, which claims the benefit of U.S. Provisional ApplicationSer. No. 60/109,881, filed on Nov. 25, 1998 and is aContinuation-in-Part of Ser. No. 09/111,094, filed on Jul. 6, 1998, nowU.S. Pat. No. 6,102,866, issued Aug. 15, 2000, all of which areincorporated herein by reference in their entireties. The latterapplication is a continuation-in-part of U.S. patent application Ser.No. 08/730,107, filed Oct. 15, 1996 now issued as U.S. Pat. No.5,776,062.

FIELD OF THE INVENTION

The present invention relates to medical imaging/biopsy systems, andmore particularly, to an enhanced system that employs x-ray imaging andtargeted ultrasound imaging in a combinative, spatially correlatablemanner that is particularly apt for breast imaging/biopsy procedures.The invention further relates to targeted ultrasound features that yieldplural modalities of operation as well as improved biopsy capabilitiesand a user interface system for facilitating targeting of a medicalinstrument to an area of interest within a patient's breast.

BACKGROUND OF THE INVENTION

The benefits of early detection and tissue diagnosis of potentiallesions and/or suspicious masses within the body is now wellestablished. Indeed, as medical practice and managed care plans continueto evolve, the role of early detection and tissue diagnosis isever-increasing. With such emphasis, both efficacy and efficiency are ata premium. Specifically, reduction of the time requirements of highlytrained medical personnel, patient office visits and medical equipmentcosts (e.g., via use of multiple-purpose equipment) are primaryobjectives for procedures utilized in the early detection and tissuediagnosis of potential lesions and otherwise suspicious masses.

Of particular ongoing interest is the area of mammography and breastbiopsy. Currently, it is common for patients to receive regularscreening mammograms, wherein two x-ray images are generated for eachbreast in order to identify potential lesions or masses suspicious formalignancy. In the event of equivocal screening mammograms, furtherx-ray or ultrasound imaging/exams may be performed to obtain additionalinformation. The obtainment of a diagnostic mammogram and/or anultrasound exam requires another patient office visit and additionalmedical personnel time. For example, if the presence of a suspiciousmass is confirmed, an ultrasound procedure may be performed in order tofurther characterize the mass. Specifically, a free-hand procedure canbe performed in which a hand-held ultrasound probe is manipulated on thebreast while viewing a display to obtain depth-profile information. Ascan be appreciated, location of a potential lesion/suspicious mass canbe difficult, and the ultrasound images obtained are frequentlydifficult to mentally associate with the x-ray images. As such, theability to utilize ultrasound technologists as opposed to experiencedphysician specialists to perform most breast ultrasound procedures islimited.

Should a breast lesion show signs of malignancy pursuant to diagnosticmammography or ultrasound, a breast biopsy is typically performed.Needle localized surgical biopsy means have recently been giving way tostereotactic x-ray biopsy with automated core needles and tissue removalsystems. A patient is typically positioned prone (e.g., on a solidtable) with the breast immobilized within a predetermined frame ofreference (e.g., the breast passes through an opening in the table andis immobilized between opposing compression plates). Stereotactic X-rayimages are then generated (e.g., via x-ray film or digital imaging) forreview by medical personnel to identify a specific location of interest(e.g., corresponding with a potential lesion or suspicious mass) withinthe predetermined frame of reference. A puncture instrument, mounted inpredetermined relation to the predetermined frame of reference, is thenpositioned/utilized to obtain a sample of tissue from the location ofinterest. Of note, current state-of-the-art breast biopsy systemsinclude the MAMMOTEST®, MAMMOVISION® and SENOSCAN™ products offered byFischer Imaging Corporation of Denver, Colo. Such systems are furtherdescribed in U.S. Pat. Nos. 5,078,142, 5,240,011, 5,415,169, 5,526,394and 5,735,264, hereby incorporated by reference in their entirety.

While breast lesions may typically be biopsied utilizing stereotacticx-ray imaging, only recently have technical improvements in ultrasoundallowed certain lesions to be biopsied under ultrasound guidance (i.e.,with hand-held ultrasound probe and/or biopsy means). In this regard,ultrasound may be preferred due to the lack of ionizing radiation andthe established availability of real time imaging to reduce proceduretime.

Recent developments in tissue removal systems have resulted in larger,heavier devices that are difficult for a physician to use in conjunctionwith free-hand ultrasound guidance. As an example, the MAMMOTOME™ fromBiopsys Medical, Inc. of Irvine, Calif. allows rapid removal of breasttissue through a small puncture hole in the breast. Due to the weightand size of the device, physicians are performing more stereotacticx-ray procedures with the MAMMOTOME™ due to the solid support of thedevice by prone stereotactic tables.

In the event that analysis of tissue by histopathologic techniquesindicates that a lesion or undesirable mass should be removed from abreast, the surgeon will typically review the various breast imagespreviously obtained to develop a therapeutic surgical strategy, with thegoal of removing the entire potential lesion and/or suspicious masswhile achieving acceptable cosmetic results.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an enhancedimaging/biopsy system that can reduce trained medical personnel timerequirements in diagnostic and biopsy procedures for tissue diagnosis.It is a related objective to provide such a system in a cost-effectivemanner; namely through the provision of a system having relativelyexpensive components that can be utilized for multiple medicalprocedures combinatively employed in a single system.

A further objective of the present invention is to provide an enhancedimaging/biopsy system for obtaining spatially correlatedthree-dimensional image information regarding a location of interest inthe body, such system being apt for the obtainment of three-dimensionalimage information regarding a potential lesion or suspicious mass in afemale patient's breast. It is a further objective to provide suchinformation in a manner allowing for enhanced use of tissue removalsystems used for obtaining tissue samples from the body, includingspecifically, tissue from a potential lesion or suspicious mass within afemale patients breast. Such information may also be used in conjunctionwith other targeted instruments such as guide wire placement devices andinstruments for ablation, delivery, etc.

Yet another objective of the present invention is to provide an enhancedimaging/biopsy system for obtaining depth-related image information fordiagnostic use and for otherwise yielding biopsy-related control andaccess advantages.

These objectives and additional advantages are met by various aspects ofthe present invention. In this regard, one aspect of the presentinvention provides for the combinative use of x-ray imaging and targetedultrasound imaging. More particularly, this inventive aspect providesfor the transmission of x-ray radiation through a selected bodyregion-of-interest within a predetermined, three-dimensional frame ofreference to obtain x-ray image data corresponding with one or morex-ray images. Additionally, an ultrasound signal is directed into alimited, selectively targeted portion of the x-rayed body region ofinterest to provide ultrasound image data corresponding with one or moreultrasound images of the targeted portion of the selected body region.The x-ray and ultrasound image data are acquired in spatial co-relationby utilizing x-ray imaging means and ultrasound imaging means eachsupportably positioned in known co-relation to the predetermined,three-dimensional frame of reference. This arrangement allows the x-rayand ultrasound image data to combinatively provide correlated,three-dimensional image data corresponding with the body region ofinterest. In turn, the spatially correlated information allows for anenhanced medical diagnosis of a given location of interest within thebody region (e.g., potential lesion or suspicious mass in a breastapplication) and enhanced biopsy options in relation thereto.

In an additional aspect of the present invention, an ultrasound imagingmeans is provided that is advantageously positionable in direct contactwith the body region of interest for optimal ultrasound imageacquisition. More particularly, in breast imaging applications, opposingcompression plates may be employed to immobilize a patient's breastwithin the predetermined, three-dimensional frame of reference, whereinan opening is provided in one of the compression plates for selectivelypositioning an ultrasound imaging head (e.g., comprising a linearultrasound transducer array) therethrough in contact with the patient'sbreast for imaging. The ultrasound imaging means may be positioned belowand on either side of a center axis of a patient support table, oralternatively, may be positioned below and in substantially coaxialrelation to a patient support table.

In another aspect of the present invention, a locating means (e.g., animage data processor with display/user interface) is provided for usingx-ray and ultrasound image data to identify a particular location ofinterest within the body region of interest; and a biopsy means isprovided for obtaining a sample from the identified location ofinterest. In this regard, the biopsy means may include positioning meansfor selectively and supportably positioning an elongated punctureinstrument or other tissue removal system relative to the predetermined,three-dimensional frame of reference, including for example positioningat a desired entry angle.

In a further aspect of the present invention, an ultrasound imagingmeans is provided that comprises a means for selectively positioning anelongated ultrasound imaging head in a known position relative to thepredetermined, three-dimensional frame of reference, includingangulation of the ultrasound imaging head relative to the predeterminedframe of reference. In the latter regard, the imaging head may be angledto image a layer, or “slice,” of the body region of interest from adirection orthogonal to a direction from which an angled punctureinstrument or other tissue-removal system may be advanced within suchlayer (i.e., the longitudinal axes of the imaging head and punctureinstrument are substantially parallel). Such ultrasound imaging allowsfor processor simulation/display of a biopsy procedure using atissue-removal system from a given biopsy position, as well as real-timeimaging/control of a biopsy device as it is actually advanced into thebody region of interest.

In an additional aspect of the present invention, an ultrasound imagingmeans is provided that comprises a positioning means for supportably andselectively positioning an ultrasound imaging probe in known spatialrelation to the predetermined, three-dimensional frame of reference,while also and alternatively allowing the ultrasound imaging probe to bedisengaged from the positioning means and manually manipulated inhand-held procedures. More particularly, the positioning means maycomprise a holder means for selectively receiving an ultrasound imagingprobe that is also adapted for hand-held use, wherein the probe may beselectively employed for hand-held manipulation or alternativelypositioned within the holder means (e.g., via sliding and/or “snap-in”engagement). In the later regard, the positioning means may be employedto supportably position the ultrasound imaging probe in predeterminedrelation relative to the predetermined three-dimensional frame ofreference to obtain depth information in a desired layer, or “slice” ofthe body region of interest. Further, the positioning means may compriseone or more drive means for providing at least partial automatedpositioning of the ultrasound imaging probe (e.g., for automated Xand/or Y dimension positioning and/or for automated rotationalpositioning about a Z axis within an XY plane).

As indicated above, x-ray images may be employed to select a limited, ortargeted, portion of the x-rayed body region of interest to be imagedutilizing the ultrasound signal. Such targeted ultrasound imaging avoidsthe acquisition, storage and processing of unneeded imaging data, andotherwise facilitates efficient use of medical personnel time, andotherwise advantageously accommodates direct contact with the bodyportion to be imaged. Further, where necessary, the provision of ahand-held ultrasound imaging option provides practitioners with addedflexibility as may be desirable in certain applications.

According to a further aspect of the present invention, an ultrasoundimaging apparatus is provided that has an improved imaging focal depth.It has been noted that a linear array of transducer elements may have afocal depth that is only a portion of the thickness of a patient'simmobilized breast. In this regard, in order to provide for morecomplete imaging for a range of patients, it is desirable to provide agreater focal depth. In particular, it would be desirable to provide afocal depth approaching to accommodate a range of patients andprocedures. A corresponding apparatus with improved focal depth includesa probe structure supporting a transducer array that includes at least afirst set of transducer elements disposed a first distance from thesignal interface surface of the probe structure and a second set oftransducer elements disposed a second distance from the signal interfacesurface. The first and second sets of elements thereby provide acombined focal depth that is greater than the focal depth that would beprovided by either of the transducer sets considered alone. In apreferred implementation, a transducer array includes 7 or more columnsof array elements where each column is disposed a different distancefrom the signal interface surface of the probe structure. Such astructure provides for improved imaging for a range of patients.

In accordance with a still further aspect of the present invention, adisplay is provided proximate to the patient's breast in order tofacilitate real time monitoring of insertion of a medical instrumentinto the patient's breast. The associated apparatus includes: animmobilizer for immobilizing the patient's breast; a first graphicaldisplay for displaying one or more images of the patient's breast so asto permit identification of an area of interest within the patient'simmobilized breast; a medical instrument operative for insertion to theidentified area of interest within the patient's breast; and a secondgraphical display, separate from the first graphical display and locatedproximate to the patient's immobilized breast, for providing real timeimages of the patient's compressed breast so that a user can monitorinsertion of the medical instrument to the identified location ofinterest using the second graphical display located proximate to thepatient's immobilized breast. Preferably, the second graphical displaycan be translated and rotated to facilitate viewing during a medicalprocedure In one embodiment, the patient is supported in a proneposition on a table with the breast under examination protruding throughan opening in the table and the second display is disposed beneath thetable for convenient viewing. Real time images such as ultrasound imagescan be monitored on the second display during insertion of a medicalinstrument such as a biopsy needle for improved guidance and confidenceregarding sampling of suspicious masses.

According with a still further aspect of the present invention, animproved graphical interface is provided for guiding a user through amedical procedure. The associated method includes the steps of:providing a mammographic medical device for use in performing a medicalprocedure on a patient's breast; providing a display device having agraphical viewing area; providing a processor operative to drive thedisplay device so as to display selected information in the viewingarea; operating the display device using the processor to provide afirst display whereby the user is presented with options correspondingto different operating modes of the medical device; operating theprocessor in response to an input regarding the operating mode toprovide instructions for operating the medical device to obtain firstand second images, where at least one of the images is an ultrasoundimage; operating the processor to display the images in a first portionof the graphical viewing area and provide graphical objects in a secondportion of the viewing area for use in entering information related tothe medical procedure; and using the first and second images to performa medical procedure on the patient's breast.

Preferably, one of the images is an x-ray image and the other image isan ultrasound image. In response to prompts provided via the displaydevice, the user can identify a location of interest within thepatient's breast on each of the first and second images. The user mayalso enter certain image enhancement functions and enter additionalinformation such as needle type using the display device. In oneimplementation, the processor is operative for displaying a projectedpenetration path of a medical instrument in superimposition on at leastone of the images. The processor may further be operative for comparingan actual penetration path to the projected penetration path to identifyany deviation therebetween and, if desired, to provide appropriatewarnings. The graphical user interface system thereby provides enhancedfunctionality, provides simple to follow instructions for medicalpersonnel and allows for close monitoring of a medical procedure forincreased accuracy and confidence in the results.

Additional features and advantages of the present invention will becomeapparent upon consideration of the further description provided herein.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a stereotactic x-ray imaging system withintegrated ultrasound imaging and biopsy components combinativelydefining one embodiment of the present invention with a centralpatient/table portion cutaway to show key components.

FIG. 2 is a partial end cross-sectional view of the embodiment of FIG. 1cut along AA.

FIG. 3 is a partial side cross-sectional view of the embodiment of FIG.1 cut along BB.

FIG. 4 is a perspective view of the immobilization, ultrasound imagingand biopsy assemblies of the embodiment of FIG. 1.

FIG. 5 is a perspective view of an ultrasound imaging head employable inthe present invention.

FIG. 6 illustrates spatially correlated x-ray and ultrasound images of apotential breast lesion/suspicious mass obtainable with the presentinvention.

FIG. 7 illustrates a side-view of an alternative embodiment of anultrasound imaging assembly comprising the present invention.

FIG. 8 illustrates a partially cut-away end view of the alternateultrasound imaging assembly embodiment of FIG. 7.

FIG. 9A is a schematic diagram of a linear ultrasound probe head arrayin accordance with the present invention.

FIG. 9B is a schematic diagram illustrating an ultrasound signal profilefor the probe of FIG. 9A.

FIG. 9C is a schematic diagram of a planar ultrasound probe head arrayin accordance with the present invention.

FIG. 9D is a schematic diagram showing an ultrasound signal profile forthe probe head of FIG. 9C.

FIGS. 10-20 show various screens of a user interface system inaccordance with the present invention.

DETAILED DESCRIPTION

FIGS. 1-6 illustrate one embodiment of a diagnostic ultrasound/x-raybiopsy system comprising the present invention, as adapted formammography/breast biopsy use.

Generally, the system comprises a support assembly 10 having a patienttable 12 with breast-opening 14 therethrough, an immobilization assembly30 for immobilizing a patient's breast within a predetermined XYZ frameof reference under the opening 14 of table 12, an x-ray imaging assembly40 for providing two-dimensional x-ray images (e.g., X-Y images) of thepatient's immobilized breast in correlated spatial relation to thepredetermined XYZ frame of reference, and an ultrasound imaging assembly100 for providing orthogonal depth-profile images (e.g., X-Z, Y-Z and/orX, Y-Z images) of the immobilized breast in correlated spatial relationto the predetermined XYZ frame of reference. A biopsy assembly 50 havingpuncture instrument 52 is also provided for obtaining samples from apatient's breast while the breast is immobilized in the predeterminedXYZ frame of reference. A display/processor assembly 60 is provided forrecording/displaying the various images obtained/generated, fordetermining the coordinates of a user-identified location of interestwithin the breast and for monitoring/controlling/simulating the positionof the various positionable assembly components.

As will be appreciated, the illustrated embodiment may utilize thex-ray, automated biopsy and other functionalities embodied in thecurrent MAMMOTEST® and MAMMOVISION® products of Fischer Imaging Corp. ofDenver, Colo., U.S.A. In this regard, the present invention allows forthe integration and effective use of ultrasound imaging with suchproducts, thereby allowing medical equipment cost efficiencies to berealized. As noted previously, the MAMMOTEST® and MAMMOVISION® productsinclude features corresponding with the disclosures in U.S. Pat. Nos.5,078,142, 5,240,011 and 5,415,169, and 5,735,264, which areincorporated by reference in their entirety.

Support assembly 10 further includes pedestal 16 and cantilevered firstand second support arms 20 and 22, respectively, for supportablyinterfacing the breast immobilization assembly 30, x-ray imagingassembly 40, ultrasound imaging assembly 100 and biopsy assembly 50 in apredetermined spatially correlated manner. First and second supportsarms 20 and 22 can be jointly pivoted relative to pedestal 16, therebyproviding imaging/biopsy access to the breast from different directions(e.g., 0°, +90° and −90° relative to the table longitudinal axis).Additionally, second support arm 22 can be selectively pivoted relativeto first support arm 20, to provide for stereotactic x-ray imaging(e.g., +15° and −15° relative to the first support arm longitudinalaxis).

Breast immobilization assembly 30 is supported on first support arm 20and includes a stationary face plate 32 and opposing compression paddle34 for immobilizing a patient's breast therebetween. Compression paddle34 is x-ray transmittent and further includes a window 36 for directbreast access by the ultrasound imaging assembly 100 and/or biopsyassembly 50. Compression paddle 34 is selectively positionable alongfirst support arm 20 (e.g., via motorized and position sensor systems)for controlled, registered movement toward/away from face plate 32 toaccommodate breast positioning/removal and differing breast sizes.Compression paddle 34 can be readily removed from/interconnected to thefirst support arm 20 to accommodate the selective use of compressionpaddles of differing sizes, shapes, window positions, etc. As shown inFIG. 1, compression assembly 30 may further include selectivelyadvanceable/retractable auxiliary side paddles 38, each having optionalopenings for breast access (e.g., by a puncture instrument or anultrasound imaging head) for further compression/breast immobilizationwithin the predetermined XYZ frame of reference, and particularly duringuse of biopsy assembly 50. In this regard, compression paddle 34 andface plate 32 are intended to define a breast imaging area ofsubstantially common thickness and to immobilize such area duringimaging/biopsy procedures, and to otherwise provide direct access to thebreast for targeted ultrasound imaging/biopsy procedures.

X-ray imaging assembly 40 includes x-ray tube source 42 mounted on theend of second support arm 22 and x-ray receiver/imager 44 mounted onfirst support arm 20. As will be appreciated, x-ray tube source 42provides x-ray radiation having a center axis C substantiallyperpendicular to the fronts of face plate 34 and x-ray receiver/imager44, such x-ray radiation having a focal point positioned along thecenter axis C at a determinable location between the face plate 32 andcompression paddle 34 during use. In this regard, and by way of exampleonly, the predetermined XYZ frame of reference can be defined in theillustrated embodiment in relation to an X-Y plane corresponding withthe front surface of the face plate 32 and/or parallel back surface ofcompression paddle 34, together with orthogonal X-Z and Y-Z planeswithin which the x-ray radiation center axis passes (i.e., all threeplanes being orthogonal). X-ray opaque markings (not shown) can beprovided on compression paddle 34 and/or face plate 32 to facilitatespatial correlation of the radiation center axes and x-rayreceiver/imager.

In the illustrated embodiment, the x-ray receiver/imager 44 is disposedin abutting relation with the face plate 32. X-ray receiver/imager 44may comprise an image receptor consisting of a removable radiographicfilm cassette (e.g., for full-field breast imaging) and/or digitalcamera (e.g., for partial field, real-time imaging/display). In thelatter regard, a partial field, digital CCD camera 46 (e.g., having a 5mm×10 mm or 5 mm×5 mm imaging area) may be disposed for selective,driven XY movement (e.g., via a servo-drive arrangement) in registeredrelation to the predetermined XYZ frame of reference.

In the illustrated embodiment, ultrasound imaging assembly 100 andbiopsy assembly 50 are selectively and alternatively connectable toopposing sides of first support arm 20 via connection/locking handles102 and 55, respectively. Additionally, biopsy assembly 50 may bemounted in an axially aligned manner on first support arm 20 for breastaccess through window 36. A reference, or “home,” position for eachassembly in a given mounted location is known relative to thepredetermine XYZ frame of reference. Further, positioning of the variouscomponents of each assembly during use is automatically determinable viaposition sensor/control systems. As will be appreciated, suchpositioning can be automated via corresponding processor-controlled,servo motors.

Biopsy assembly 50 comprises a punction sub-assembly 54, which includespuncture instrument 52, and positioner sub-assembly 56. Positionersub-assembly 56 includes horizontal axis and vertical control motors 58and 60, respectively, for selective sideward movement and upwardangulation of the punction instrument 52. By way of example, punctionsub-assembly 56 may comprise the AUTOGUIDE™ assembly of Fischer ImagingCorporation. As will become appreciated, the illustrated embodiment maybe particularly apt for use with punction subassemblies for obtainingsamples having relatively large cross-sections, including, for example,the MAMMOTOME™ from Biopsys Medical, Inc. of Irvine, Calif.

Ultrasound imaging assembly 100 comprises an ultrasound imaging head, orprobe, 110 interconnected to arm assembly 130 and, in turn, to XYZultrasound positioning assembly 140. As will be further explained, XYZultrasound positioning assembly 140 is employed to selectively positionultrasound imaging head 110 through the window 36 of compression paddle34 to establish direct breast contact for targeted ultrasound imaging indeterminable spatial relation to the predetermined XYZ frame ofreference.

As shown in FIG. 5, ultrasound probe 110 may include an elongatedhousing 112 with an elongated ultrasound transducer module 114positioned therein. Ultrasound transducer module 114 provides anultrasound signal having a focal point on a signal center axis at alocation between compression paddle 34 and face plate 32. Ultrasoundtransducer module 114 may include, for example, a phased linear array ofultrasound transducers positioned along a longitudinal axis of theultrasound probe 110. The ultrasound probe 110 emits signal pulses anddetects corresponding echo pulses to generate the depth-profile images.More particularly, and as will be appreciated by those skilled in theart, detected echo pulses will result from ultrasound transmissivitydifferences (i.e., ultrasound impedance mismatches) at tissue-typetransition areas (e.g., transitions between healthy tissue and apotential lesion/suspicious mass) and at structural obstructions (e.g.,the front surface of face plate 32). The housing 112 of ultrasound probe110 may include a recess 118 (exaggerated in FIG. 5) for receiving acold-pack 120 for orthogonal application to a biopsy site after a biopsyprocedure. Applying pressure and a cold medium directly over a biopsysite in the breast has been shown to reduce hematoma bleeding andbruising.

XYZ ultrasound positioning assembly 140 includes X, Y and Z platforms142, 146 and 148, respectively, mounted for selective, registeredmovement on corresponding support members 152, 156 and 158 relative tothe predetermined XYZ frame of reference. In this regard, XYZpositioning assembly 140 may include internal X, Y and Z opticalposition encoders. XYZ positioning assembly 140 can further include X, Yand Z motor drives for automatic, selective positioning of ultrasoundimaging head 110 in registered XYZ relation to the predetermined XYZframe of reference. The XYZ positioning assembly 140 may also includecounterbalance and electro-lock components to accommodate ready manualpositioning and to maintain a selected ultrasound imaging/biopsyposition, respectively.

Arm assembly 130 is provided to allow the ultrasound imaging probe 110to be rotated about one or more of selected X, Y and Z axes to obtain adesired pitch, roll and/or yaw orientation). For example, arm assembly130 can be controlled to selectively rotate the longitudinal axis, orpitch, of probe 110 so that the ultrasound signal may be employed toobtain depth-profile image in a plane, or “slice,” within which anupwardly angled punction instrument 52 of biopsy assembly 50 may beorthogonally advanced, as will be further discussed.

In the illustrated embodiment, arm assembly 130 includes pivot arm 132pivotally interconnected to XYZ ultrasound positioning assembly 140 viaa lock/release mechanism (not shown) for selective, centered rotation ofprobe 116 about axis YY.

Arm assembly 130 further includes arm 134 rotatably interconnected toarm 132 via a lock/release mechanism (not shown) for selective, centeredrotation of probe 116 about axis XX, and arm 136 rotatablyinterconnected to arm 134 via a lock/release mechanism (not shown) forselective, centered rotation of probe 116 about axis ZZ. Internaloptical encoders (not shown) may be provided at the various arminterconnections, wherein the pitch, roll and/or yaw of probe 110 isautomatically determinable in relation to the predetermined XYZ frame ofreference. In this regard, internal automated micro-positioners may alsobe utilized under processor control.

As will be appreciated, the ultrasound signal may be scanned to obtaindepth-profile information for a predetermined layer, or “slice,” withinthe region of interest. By way of primary example, such scanning may beprovided electrically by driving a phased linear array of transducerscomprising probe 110 in a known manner and/or via manual orautomatic-driven control of XYZ positioning assembly 140 to mechanicallymove ultrasound imaging head 110.

As shown in FIG. 6, display/processor 60 includes a display screen 62for displaying the acquired x-ray images on a first portion 62 a anddisplaying corresponding depth-profile ultrasound images on a secondportion 62 b, each in registered co-relation to the predetermined XYZframe of reference. Display/processor 60 may further include a userinterface means 64, e.g., keyboard 65 and mouse 66 and screen pointcursor 68 (e.g., on both display portions 62 a, 62 b), wherein a usermay identify (e.g., click upon) a specific location-of-interest withinboth an x-ray image and corresponding ultrasound image (e.g.,corresponding with a potential lesion or suspicious mass), e.g., forautomatic processor determination of the three-dimensional coordinatesof the location within the predetermined XYZ frame of reference. Userinterface means may further allow for user selection/display of aparticular desired ultrasound depth-profile image, e.g., via mouse 66and screen “slice” cursor 70 on the x-ray image display portion 62 a.More particularly, screen “slice” cursor 70 may be employed to identifya particular slice, or layer, of an X-Y x-ray image for which acorresponding ultrasound depth-profile image is to be obtained (e.g.,thereby resulting in processor-assisted positioning and imaging usingprobe 110) and/or accessed and displayed (e.g., where such ultrasounddepth-profile image has been previously obtained/stored for selectivesubsequent review).

As indicated, display/processor 60 may be operatively interconnected(e.g., via electrical lines 80) to the various positionable assemblycomponents for monitoring/controlling their respective positionsrelative to the predetermined XYZ frame of reference, including thepositionable components of immobilization assembly 30, x-ray imagingassembly 40, ultrasound imaging assembly 110 and biopsy assembly 50. Byway of primary example, display/processor 60 may determine thethree-dimensional coordinates of a specific location of interest, asdescribed above, and in turn assist/control the positioning of biopsyassembly 50 so as to position the assembly for obtainment of a tissuesample from the location of interest. In this regard, thedisplay/processor 60 may also be employable to visually project, orsimulate, the entry of a punction instrument 52 into a given location ofinterest, thereby allowing physicians the opportunity to insure anoptimal positioning for biopsy entry prior to an actual biopsyprocedure. Since three-dimensional visualization of a potentiallesion/suspicious mass can be provided by the present invention, andsince the disclosed arrangement allows for breast access by biopsyassembly 50 from a plurality of aspects (e.g., by selective mounting oneither side of or coaxial along support arm 20), such simulated biopsymodeling may prove to be of particular advantage.

The present invention allows for spatial correlation of the x-ray andultrasound images utilizing various techniques. By way of primaryexample, it can be appreciated that the X-Y x-ray images obtained can bereadily correlated to the predetermined XYZ frame of reference since theposition and attributes of x-ray source 42 and x-ray receiver/imager 44are each known in relation to the predetermined XYZ frame of reference.Additionally, in stereotactic imaging procedures, the two X-Ystereotactic x-ray images can be employed to obtain a Z location forparticular location of interest relative to the predetermined XYZ frameof reference utilizing known triangulation techniques, as will beappreciated by those skilled in the art. Further, the XYZ positioning ofultrasound imaging head 110 is determinable relative to thepredetermined XYZ frame of reference, as noted above. Relatedly, in theembodiment described above, the ultrasound imaging head 110 willemit/detect ultrasound signals in substantially the same plane as thesurface of compression paddle 34 contacting the imaged breast. Theposition of such surface relative to the predetermined XYZ frame ofreference (e.g., the Z distance to face plate 32) is also determinable.In view of the foregoing, it can be seen that utilizing known ultrasoundpulse/echo techniques a depth profile comprising a potentiallesion/suspicious mass can be spatially related in a reliable manner tothe acquired x-ray images.

In use, a patient can be positioned on the table 12 with a breastpositioned through opening 14. Compression paddle 34 is then advancedalong first support arm 20 to compress the breast to define across-sectional imaging area having a common thickness and to otherwiseimmobilize the breast in a set position within the predetermined XYZframe of reference. X-ray imaging assembly 40 is then selectivelypositioned to obtain the desired x-ray images. Such x-ray images arethen reviewed using display/processor 60, to identify, analyze and orotherwise confirm the presence and location of a potential lesion orsuspicious mass for ultrasound imaging. Alternatively, the generallocation of a potential lesion or suspicious mass may already be knowndue to prior x-ray screening.

In either case, to proceed with ultrasound imaging, the patient shouldbe positioned/repositioned so that the potential lesion or suspiciousmass is positioned within the accessible field of view of ultrasoundimaging head 110 when it is maneuvered through the window 36 ofcompression paddle 34 in direct contact with the imaged breast. As canbe appreciated, in order for the present invention to yield spatiallycorrelatable image information with respect to a potential lesion orsuspicious mass, new x-ray and corresponding ultrasound images should begenerated for each position in which a breast is immobilized within thepredetermined XYZ frame of reference. As such, the benefit of utilizinga digital camera 46 in x-ray receiver 44 for partial field, real-timeimaging via display/processor 60 can be readily understood.

Once it is verified that the area of interest is positioned adjacent tothe window 36, ultrasound imaging probe 110 is positioned through thewindow 36 and a series of ultrasound images are obtained and displayedon display/processor 60. Cursor 66 control of the ultrasound imagestaken across the area of interest provides additional, valuableinformation as to the type of potential lesion/suspicious massoriginally noted on an original mammogram. For example, with propertraining of ultrasound and x-ray imaging techniques, physicians may ruleout the possibility of a solid mass in favor of a fluid-filled cyst. Or,additional ultrasound characteristics may aid the physician in making adefinitive diagnosis.

If it is determined that a biopsy is desired, the specific location fromwhich tissue is to be obtained can be identified using mouse 66 toposition screen point cursor 68 on both the x-ray image and correlatedultrasound depth-profile image on display/processor 60.Three-dimensional coordinates can then be determined and utilized bydisplay/processor 60 to control positioning of biopsy assembly 50. Inthis regard, it will be appreciated that specific attributes of theparticular punction subassembly 54 utilized will have been previouslyentered into by display/processor 60. Further, and as noted above, givensuch previous input information, display/processor 60 may be employed tosimulate the advancement of punction instrument 52 into the breast froma given potential position, thereby allowing the physician to determineif breast biopsy access from a different position may be more desirable.

After the biopsy subassembly 50 is positioned as desired, biopsyprocedures may be completed. In conjunction with such procedures, theultrasound imaging head 110 may be utilized to provide continuous,successive depth profile images, thereby allowing for real-timemonitoring and user control of the advancement of the punctioninstrument 52 into the breast. More particularly, when the punctioninstrument is positioned at an angle θ as illustrated in FIG. 2,ultrasound imaging head 110 may be similarly angled at θ (e.g., relativeto horizontal) so as to yield real-time ultrasound depth-profile imagesof the layer into which punction instrument 52 is advanced. After biopsyprocedures are completed, ultrasound imaging head 110 may berepositioned so as to allow for pressure application of a cold pack 120.

Referring to FIGS. 2-4, an ultrasound display system is generallyidentified by the reference numeral 300. In order to facilitate certainprocedures such as a sampling of a suspicious lesion or tissueharvesting (or other targeted procedures such as guide wire placement,laser ablation or treatment delivery), it is desirable to provide anultrasound display system in proximity to the patient's compressedbreast. In this regard, the availability of a substantially real timeultrasound display is desirable to monitor the actual penetration pathof a biopsy needle or other instrument into the patient's breast, forexample, to verify that the instrument traverses the desired tissue andproperly targets the area of interest. In the latter regard, it will beappreciated that certain instruments such as biopsy needles may have atendency to deflect, particularly if the instrument contactscalcifications or other dense tissue structure. Accordingly, theavailability of an ultrasound display system in proximity to thepatient's breast allows the physician to verify that the instrument isproperly targeting the area of interest and has not strayed due todeflection or otherwise. Moreover, the physician may wish to verify thata breast lesion has been sampled after activation of the biopsyinstrument. Again, the availability of the ultrasound display system inproximity to the patient's breast facilitates such monitoring of asampling process and sample verification.

In the illustrated embodiment, such monitoring is facilitated byproviding an ultrasound display system 300 in proximity to the patient'sbreast under the table 12. In this regard, the system 300 may be mountedto the table 12, the pedestal 16 or another part of the support assembly10, or may be otherwise positionable in proximity to the patient'sbreast beneath the table 12.

As noted above, the illustrated embodiment allows for sampling fromvarious positions, including from either side of the patient's breast.In order to allow for convenient positioning of the ultrasound displaysystem 300 for monitoring during a medical procedure, the illustratedsystem includes a support and positioning assembly 306. Morespecifically, the system includes a monitor 302 having a screen 304 fordisplaying ultrasound images. The illustrated assembly 306 allows for athree-dimensional translation of the monitor 302 as well as angularorientation of the screen 304 for easy viewing by a physician duringsuch a medical procedure. The various types of motion that areaccommodated by the assembly 306 are generally indicated by arrows inFIG. 3.

The support and positioning assembly 306 includes an articulatedpositioning system including an upper arm 308 and a lower arm 314. Theupper arm is interconnected to the table 12 by way of a swivel mechanism310 and an upper pin 312. The swivel mechanism 310 allows the assembly306 to rotate relative to the Y axis as indicated in FIG. 3. Inaddition, the upper arm can pivot about upper pin 312. The upper arm 308and lower arm 314 are interconnected in a manner that allows forrelative swiveling and pivoting motion therebetween. In this regard, acentral pivoting mechanism 316 allows for pivotal motion between thearms 308 and 314.

The lower arm 314 is also rotatable about pin 318 so as to allow forrelative swiveling motion between arm 314 and arm 308. The lower arm 314in turn is interconnected to the monitor 302 in a manner that allows forswiveling and pivoting motion therebetween. In this regard, lowerpivoting mechanism 320 allows for pivotal motion between 314 and monitor302. The monitor 302 can swivel relative to the arm 314 by rotatingabout lower pin 324. The lower pivoting mechanism 320 allows forrotation about the post 322. It will thus be appreciated that theassembly 306 allows for three-dimensional translation of the monitor toa position as desired by the physician/user, and also allows forpositioning of the screen 304 in a desired angular orientation relativeto both vertical and horizontal planes. It will be appreciated thatother types of positioning mechanisms including slides, telescopingarms, and linear drive mechanisms can be used to provide some or all ofthe illustrated motions, and such motions may be actuated manually ordriven by motors.

FIGS. 9A-9D show different ultrasound probe head configurations that mayused to achieve different ultrasound signal characteristics inaccordance with present invention. Referring first to FIG. 9A, a frontperspective of an ultrasound head 900 in accordance with the presentinvention as shown. The illustrated head 900 is a linear head includinga linear array of conventional ultrasound probe elements 902. Each suchelement includes an ultrasound transducer operative for bothtransmitting ultrasound signals to the patient and receiving echosignals returning from the patient. For example, the ultrasound elementsmay include a piezo transducer that is operative to transmit ultrasoundsignals by flexing or otherwise displacing in response to inputelectrical signals. Conversely, the return signals cause the transducerelement to flex or otherwise displace thus creating an electrical outputrepresentative of the received return ultrasound signal. As is known,the wave form of the output signal provides information regarding thedensity of the tissue from which the signal was reflected. The transittime, i.e., the elapsed time between signal transmission and signaldetection, provides information regarding the distance or depth relativeto the head of the tissue that reflected the signal. In this manner, theultrasound image provides information regarding the nature and locationof tissue within the patient's breast. The illustrated head 900 mayinclude, for example, 128 elements arranged in a single row and may bedriven by, for example, a 10 MHz signal.

FIG. 9B shows a top schematic view of the probe 900. The probe headtransmits a focused ultrasonic signal 901 having a profile as generallyillustrated. In this regard, the signal includes a focal area withinwhich high quality images can be obtained. In the illustratedembodiment, the depth of this focal region is indicated by D₁. In orderto limit the ultrasound image to the area corresponding to depth D₁, theultrasound imaging system may process the return signal over acorresponding time period. Specifically, ultrasound probes are generallyoperated in a series of alternating transmit and receive time periods.During a first transmit time period, an ultrasound signal is transmittedinto the patient. At the end of the transmit time period, thetransmission signal is terminated and the probe remains available forreceiving return signals. The time at which return signals are receiveddepends on the depth of the tissue from which such signals arereflected. Thus, an image corresponding to the area indicated by D₁ canbe provided by processing the return signal over the corresponding timeperiod.

FIG. 9C shows a front perspective view of a planar ultrasound probe headarrangement. The head 904 includes ultrasound elements arranged in rows908 and columns 906. In use, the forward surface of the front column 908is disposed approximate to the patient. Thus, the various columns 908are disposed at varying distances from the patient.

FIG. 9D shows a top schematic view of the head 904 of FIG. 9C. Theelements in each of the columns 908 transmit focused ultrasound signals905. Because the columns are disposed at different distances from thepatient or at different locations relative to the signal axis, thesignals transmitted from the elements of the various columns 908 definea focal region having a depth D₂ that is greater than the depth D₁ ofthe head 900 of FIGS. 9A and 9B. The illustrated head 900 includes morethan one column 908 and may include, for example, seven or more columns.Each column may include, for example, 128 elements 906.

In certain cases, the planar array configuration of head 904 providesimaging advantages. In this regard, it is desirable to provide a focalregion depth, D₂, of at least about 5 centimeters as such depth allowsfor complete ultrasound imaging across the entire thickness of thecompressed breast for most patients. The head 904 provides such focaldepth. Accordingly, for most patients, the head 904 can provide highquality images of an area of interest within the patient's breastregardless of the location of the area of interest relative to thethickness of the patient's compressed breast.

Although the illustrated embodiment allows for utilization of x-rayimages in conjunction with ultrasound images for three-dimensionallocalization of an area of interest within a patient's breast, it willbe appreciated that such three-dimensional localization may beaccomplished using only ultrasound imaging. For example, the ultrasoundimaging assembly 100 may be initially used to obtain a scout image orimage set. In this regard, arm 136 may be positioned so that theultrasound head 116 is in a vertical orientation, i.e., substantiallyaligned with axis Y of FIG. 2. The assembly 100 can then be moved alongthe X axis of FIG. 2 so as to obtain ultrasound imaging exposures atvarious known locations along the X axis to thereby image the area ofinterest 46, e.g., in the form of multiple ultrasound image slices. Inthis manner, three-dimensional imaging information is provided for thelocation of interest 46 This information can then be used to providetargeting coordinates for the biopsy assembly 50.

During a subsequent medical procedure such as a needle biopsy, the arm136 can be rotated such that it is aligned with axis 52 of a medicalinstrument such as a biopsy needle or gun. In this manner, the imagingassembly 100 can be used to provide substantially real time imaginginformation for monitoring insertion of the biopsy needle and samplingof the location of interest 46.

FIGS. 7 and 8 pertain to an alternate embodiment of an ultrasoundimaging assembly 200. In this regard, it should be noted that while theultrasound imaging assembly 100 described hereinabove is supportablypositioned below and on one side of a center axis of patient table 12,the alternate ultrasound imaging assembly 200 is provided to besupportably positioned immediately below and in substantial coaxialalignment with patient table 12. Such positioning of the ultrasoundimaging assembly 200 allows for the alternate positioning of a biopsy aassembly 50, as described above, on either side below patient table 12,thereby yielding enhanced access to the above-noted predetermined XYZframe of reference.

As illustrated in FIGS. 7 and 8, the ultrasound imaging assembly 200 issupportably positioned on and in coaxial relation to the first supportarm 20. First support arm 20 also carries breast immobilization assembly30. As with the embodiment described above, the breast immobilizationassembly 30 includes a stationary face plate 32 and opposing compressionpaddle 34 for immobilizing a patient's breast therebetween. Compressionpaddle 34 again is x-ray transmittent and includes a window 36 fordirect breast access therethrough by the ultrasound imaging assembly 200and/or a biopsy assembly 50. Compression paddle 34 is selectivelypositionable along the first support arm 20. In this regard, a lockingmechanism portion 38 of compression paddle 34 is sized in the embodimentof FIG. 7 for positioning under at least a portion of ultrasound imagingassembly 200 to yield overall enhanced access and compactnessadvantages.

Support arm 20 may also support an x-ray image receiver/imager 244positioned in opposing relation to the x-ray tube source 42. Imagereceiver/imager 244 may comprise a removable radiographic film cassetteand/or digital CCD camera assembly for partial or full-field, real timeimaging. In the later regard, receiver/imager 244 may comprise a CCDassembly for full-field imaging as described in U.S. Pat. No. 5,526,394,hereby incorporated by reference.

With further respect to ultrasound imaging assembly 200, the assemblyincludes an ultrasound imaging probe 210 having an imaging head 212(e.g., comprising an ultrasound transducer and/or linear array oftransducers) positioned at the end of an elongated handle portion 214.The handle portion 214 is configured for selective grasping duringhand-held use and alternatively for positioning within a holder 220having a cradle-like configuration. In the illustrated embodiment, theholder 220 includes two interconnected and aligned u-shaped portions forconformally receiving a cylindrically shaped probe handle 214 (e.g., via“snap-in” and/or slide-in engagement). As will be appreciated, probehandle 214 and holder 220 may include projections and receiving slots orother means for establishing a predetermined positional relationshiptherebetween when engaged. The probe 210 may include an interconnectline 218 for transferring image data to a display/processor 60. Forpositioning relative to the predetermined XYZ frame of reference, holder220 is mounted to an XYZ positioning assembly 240.

The XYZ ultrasound positioning assembly 240 includes X, Y and Zplatforms 242, 246 and 248, respectively, mounted for selective,registered movement on corresponding support members 252, 256 and 258relative to the predetermined XYZ frame of reference (i.e., definedbetween compression paddle 34 and face plate 32). The entire assembly200 may be selectively removed from/interconnected to the support arm 20utilizing a carrier assembly 260 having a depressible hand grasp 262 forretracting/advancing a locking pin(s) that interfaces with one or moreopenings along support arm 220.

Ultrasound imaging assembly 200 further comprises a first motor assembly270 for driving X platform 242 for automated side-to-side movement ofprobe 210 in the X dimension. Similarly, ultrasound imaging assembly 200also comprises a second motor assembly 280 for automated driving ofplatform 246 for up/down positioning of probe 210 in the Y dimension.Positioning in the Z dimension may be established by moving platform 248relative to support member 258. Ultrasound imaging assembly 200 alsoincludes a third motor assembly 290 for rotational movement of theholder 220, and in turn probe 210 mounted therewithin, about the axisZZ. In this regard, holder 220 includes a microencoder for establishingthe particular desired rotational angle of the ultrasound imaging probehead 212 (i.e., and the transducer and/or transducer array thereof)relative to the ZZ axis within the XY plane defined by the face 214 ofthe probe 210.

FIGS. 10-20 illustrate screens of a user interface system that may beemployed in connection with the embodiments described above forprocedures including localization, targeting and sampling of an area ofinterest in a patient's breast. Referring first to FIG. 10, an initialscreen of the user interface system is shown. The screen may bedisplayed on a conventional display system such as an LCD or CRTcomputer monitor. For example, the screens may be displayed on thedisplay/processor assembly 60 of FIGS. 1-6.

The initial screen, as shown in FIG. 10, includes an image display area1000 and a user input area 1002. The user input area 1002 includes anumber of graphical objects or buttons corresponding to particularfunctions such that the functions can be assessed and/or implemented byactivating a cursor relative to the graphical objects, touching thegraphical objects or other inputs relative to the objects. As shown inFIG. 10, the objects include a button 1004 labeled “Mammotest”, a button1006 labeled HF-X, a button 1008 labeled “Ultrasound”, a button 1010labeled “Help”, a button 1012 labeled “U/S Image Procedure”, a button1014 labeled “Utilities” and a button 1016 labeled “HF-X OnlyUtilities”. These buttons allow the user to select as between variousoperating modes of the system. In this regard, the system may be usedfor conventional upright x-ray procedures corresponding to the buttonHF-X, prone stereotactic imaging applications corresponding to thebutton labeled “Mammotest” or, of particular relevance with respect tothe present discussion, for ultrasound-based procedures corresponding tothe buttons 1008 and 1012.

The Help button 1010 can be used to access a variety of instructionalinformation and operating information for the system. The Utilitiesbutton 1014 can be used to access various utilities screens, forexample, relating to accessing records, changing display parameters suchas brightness, etc. The HF-X Only Utilities button 1016 provides accessto utility information relating to the HF-X mode of operation. For thepurposes of the present discussion, the user may activate ultrasoundbutton 1008 in order to initiate ultrasound related procedure.

FIG. 11 illustrates a subsequent screen of the user interface system.The screen includes a display area 1102, a user input area 1104 and aninstruction area 1106. The instruction area 1106 provides instructionsto the user with regard to the current screen. In this regard, theillustrated screen includes instructions directing the user to enterpatient data and to click “Done” when finished. The user may then entera patient name, patient identification number, a physician name, a dateof procedure, a technician's initials and any other information asdesired into the display area 1102. Such information is used, forexample, for purposes of maintaining records and facilitating laterretrieval of desired images.

The user input area includes graphical objects 1108, 1110 and 1112respectively labeled “Lateral Approach”, “Target on Scout”, and print DBEntry. The Print button 1112 can be used to provide a hard copy of thescreen including, for example, the entered patient information. Thelateral approach button 1108 allows the user to indicate when a lateralapproach is being utilized for imaging the patient's breast. The Targeton Scout 1110 allows the user to indicate that a scout image is to beobtained. For example, an x-ray scout image may initially be displayedto identify the area of interest for use in positioning the targetedultrasound system. It will thus be appreciated that the sequence ofscreens presented to the user may vary depending on the specificprocedure to be implemented as indicated through appropriate entriesrelative to the displayed graphical objects.

FIG. 12 illustrates a screen which may be presented in the case wherethe user desires to obtain an initial scout image. As shown, the displayarea 1202 is blank pending acquisition of the scout image. Theinstructions in area 1204 indicate that the system is ready foracquiring the scout image and provides information regarding positioningof the x-ray tube. Specifically, the instructions indicate that thex-ray tube should be positioned to 0 degrees corresponding to a top tobottom imaging angle relative to the patient's breast. It is alsopossible for the user to skip the digital scout image by selecting theskip digital scout button 1208 in input area 1206. For acquisition ofthe scout image, the ultrasound imaging system may be removed to avoidinterference.

As noted above, the three-dimensional coordinates of a location ofinterest within the patient's breast can be identified based on adigital x-ray image and an ultrasound image. In FIG. 13, a digital x-rayimage is displayed in the display area 1302. This x-ray image can beused to identify the location of interest relative to the twodimensional image so as to allow for appropriate positioning of theultrasound imaging system.

In order to enhance the image and facilitate identification of thelocation of interest, a number of image enhancement features can beaccessed and implemented relative to the buttons provided in user inputarea 1304. These buttons include: a reverse video button for reversingthe tone of the displayed x-ray image, i.e., to provide a negative ofthe displayed image; a squeeze button for minimizing the display areaoccupied by the image; a contrast button for varying the contrast of theimage; a ruler button for providing a scale for dimensional referencewith respect to the image; a fall resolution button for displaying theimage with maximum resolution; an edge enhancement button foridentifying and enhancing the edges of displayed structural features forenhanced structure identification; an autocontrast button forautomatically fixing the contrast level; a zoom button for zooming in ona particular area of the image, for example, as identified by a cursorinput; a KV button for activating a kilovolt sensor to control the powerof an exposure; and an exposure control button for allowing the user tomanually control exposure. After the image has been displayed to thesatisfaction of the user, the user may proceed to ultrasound imageacquisition. In this regard, the instruction box 1306 providesinstructions to install the ultrasound positioner (an ultrasound imagingsystem).

FIGS. 14 and 15 illustrate a process for positioning an ultrasoundprobe. In the illustrated implementation of the present invention, thex-ray image is used in conjunction with an ultrasound image to localizean area of interest in three dimensions in the following manner. First,the x-ray image is display in the display area as shown at 1402 in FIG.14. A line within the image in the display area 1402 indicates a currentposition of the ultrasound probe. For convenient reference, an arrowheadis provided at one end of the line to indicate a rearward end of theultrasound probe. As indicated by the instructions in area 1404, theuser can position the ultrasound probe by clicking on the location ofinterest in the x-ray image. In response to this data entry, the motorsassociated with the ultrasound positioner will drive the ultrasoundprobe to the desired location relative to the two dimensions of thex-ray image.

As indicated in FIG. 15, the ultrasound probe automatically moves to theindicated point on the x-ray scout image. It will thus be appreciatedthat two dimensional coordinates of the location of interest are encodedinto the position of the ultrasound transducer. The ultrasound imagingsystem can then be used to identify the third dimension, or depth, ofthe location of interest. To this end, the ultrasound image system isactivated to provide a second image which is displayed in the displayarea 1502 as shown in FIG. 15. In order to identify the location ofinterest relative to the ultrasound image, the user first selects themark lesion button in user input area 1504 and then positions andactivates the cursor over the location of interest on the ultrasoundimage, per the instructions in area 1506. This process is illustrated inFIG. 16.

FIGS. 15 and 16 also include a select needle button in the user inputarea. It will be appreciated that different biopsy needles havedifferent dimensions which need to be accounted for in targeting thelocation of interest for sampling. Such information can be entered byusing the select needle button. In addition, it is possible inaccordance with the present invention to show a representation of aneedle on the images, for example, to project the penetration path sothat a physician can plan a sampling procedure. For example, a physicianmay wish to alter a potential penetration path in order to traverse lessbreast tissue or to avoid certain intervening structure on the way tothe location of interest.

FIG. 17 shows the results of a three dimensional localization procedure.Specifically, the target coordinates together with certain other patientand procedural information are displayed in display area 1702. Theinformation displayed in this regard may include three-dimensionalcoordinate information as well as adjusted coordinate information toaccount for certain offsets relating, for example, to the geometry ofthe needle holder and needle. Also shown in the ultrasound image in thedisplay area 1702 is a projected needle path for the sampling procedure.In order to further enhance the physician's ability to understand thedisplayed images, an indication may be provided in the display area 1702or otherwise regarding the angular orientation of the displayed images.In this regard, the illustrated display area 1702 includes an indicationthat the ultrasound positioner is rotated to a position identified as 43degrees.

FIGS. 18-20 illustrate a subsequent needle biopsy procedure. As has beendescribed above, the ultrasound probe may be aligned relative to thepenetration axis of the biopsy needle such that penetration of thebiopsy needle can be viewed in real time. This video information, whichis also displayed on the under table monitor, is shown in FIGS. 18-20.Specifically, FIG. 18 shown an initial penetration of the biopsy needletowards the location of interest. An indicated of the penetration pathis overlaid in the image relative to the biopsy needle. The biopsyneedle may deflect from its intended course, for example, due to contactwith calcifications or other dense structure within the patients breast.For this reason, the availability of real time ultrasound imaging duringthis process is an important advantage of the illustrated system. In theevent that the needle appears to be diverting from the intended course,the user can manually correct the positioning of the biopsy needle. Inthis regard, the instructions in area 1804 remind the user to considercorrecting the course by using raised needle and lower needle buttonsprovided in conjunction with the ultrasound probe positioner. Ifdesired, the illustrated system can be programmed to identify anydiversion between the actual penetration path and the projectedpenetration path so as to issue an alert or allow for automaticcorrection.

FIG. 19 shows a position of the biopsy needle prior to activation of theneedle to harvest tissue or cells from the area of interest. In thisregard, typical biopsy needle guns are operated by positioning thebiopsy needle a short distance from the location of interest and pointedtowards the location of interest and then activating the gun so that theneedle is thrown a distance through the area of interest such as underspring force. In this regard, FIG. 19 shows the pre-fire position of thebiopsy needle and FIG. 20 shows the post-fire position of the biopsyneedle. These images can be viewed in real time so that the physicianmay be satisfied that the location of interest has in fact been sampledand that the resulting biopsy will be reliable.

While the present invention has been described in relation to oneembodiment, it will be appreciated that the invention may be utilized innumerous additional embodiments and procedures. Such additionalembodiments and procedures are within the scope of the presentinvention, as defined by the claims which follow.

1. A method comprising: immobilizing a patient's breast using a selectedimmobilization assembly; imaging the immobilized breast with penetratingradiation to obtain at least one two-dimensional penetrating radiationimage of the breast; displaying the at least one penetrating radiationimage of the breast and deriving therefrom first spatial informationregarding a region of interest in the breast; positioning an ultrasoundimage display screen in close proximity to the immobilized breast bymoving the screen using an articulating supporting structure; carryingout ultrasound imaging of the immobilized breast to obtain ultrasoundimages of the breast substantially in real time and deriving therefromsecond spatial information regarding the region of interest; displayingsaid ultrasound images on said ultrasound display screen substantiallyin real time and in spatial correlation; and using said displayedultrasound images and said first and second information regarding theregion of interest to guide an insertion of a medical instrument in theimmobilized breast including by operatively interconnecting a processorwith at least the immobilization assembly and the medical instrument,wherein said processor controls the relative positions thereof toposition the medical instrument relative to said region of interest. 2.A method as in claim 1 in which said moving comprises moving theultrasound image display screen in a motion having at least four degreesof freedom.
 3. A method as in claim 2 in which said degrees of freedominclude three-dimensional translation and angular motion.
 4. A method asin claim 1 including displaying said at least one penetrating radiationimage at a penetrating radiation image display screen that is separatefrom said ultrasound image display screen.
 5. A method as in claim 1 inwhich said ultrasound images provide three-dimensional informationregarding the region of interest in the breast for needle biopsy of saidregion.
 6. A method as in claim 1 in which said at least one penetratingradiation image of the breast provides two-dimensional informationregarding the region of interest in the breast and said ultrasoundimages provide spatial information regarding at least a third dimensionregarding the region of interest.
 7. A method as in claim 1 includingproviding a computer with third spatial information regarding the regionof interest derived from said first and second spatial information, andcalculating fourth spatial information regarding a path of a medicalinstrument for penetrating the immobilized breast.
 8. A method as inclaim 7 including providing the computer with needle informationregarding parameters of a biopsy needle and using the needle informationin calculating said path.
 9. A method comprising: immobilizing apatient's breast; imaging the immobilized breast with penetratingradiation to obtain at least one two-dimensional penetrating radiationimage of the breast; displaying the at least one penetrating radiationimage of the breast and deriving therefrom first spatial informationregarding a region of interest in the breast; positioning an ultrasoundimage display screen in close proximity to the immobilized breast bymoving the screen using an articulated supporting structure; carryingout ultrasound imaging of the immobilized breast to obtain ultrasoundimages of the breast substantially in real time and deriving therefromsecond spatial information regarding the region of interest; displayingsaid ultrasound images on said ultrasound image display screensubstantially in real time; and using displayed ultrasound imagesregarding the region as displayed on the ultrasound image display screento monitor an insertion of a medical instrument in the immobilizedbreast; wherein said ultrasonic imaging comprises using an ultrasoundprobe that automatically moves to a selected position in response to theselection of a region of interest in said penetrating radiation image.10. A method as in claim 9 in which said ultrasound imaging includesscanning the breast with ultrasound beams.
 11. A method as in claim 9 inwhich said ultrasound imaging includes acoustically coupling ultrasoundtransducer with the immobilized breast through an opening in a breastimmobilizing structure.
 12. A method as in claim 9 including using amotorized structure and information from the penetrating radiationimages to automatically position ultrasound transducers relative to theregion of interest in the breast.
 13. A method as in claim 12 includingscanning at least the region of the interest with ultrasound beams fromsaid transducers.
 14. A method as in claim 9 including providing acomputer with needle information regarding parameters of a biopsyneedle, and using the needle information in calculating a breastpenetration path for said medical instrument.
 15. A system comprising: abreast immobilizing structure for securing a patient's breast in aselected position; a penetrating radiation imager selectively imagingthe immobilized breast with penetrating radiation to obtain penetratingradiation images of the breast; an ultrasound imager having a displayscreen and an articulated support structure for selectively positioningthe screen in close proximity to the immobilized breast; said ultrasoundimager selectively carrying out ultrasound imaging of the immobilizedbreast and thereby obtaining ultrasound images of the breastsubstantially in real time; an image display and a computer coupled withthe penetrating radiation imager to receive said images therefrom, withthe ultrasound imager to receive said ultrasound images therefrom, andwith the display to selectively display the penetrating radiation imagesand the ultrasound images, and configured to process the images and userinputs to derive spatial information regarding a region of interest inthe immobilized breast; and a medical device for insertion into apatient and a controller operatively connected with the computer andwith the medical device and using said displayed ultrasound images andsaid spatial information regarding the region of interest to automateguidance of an insertion of the medical device in the immobilizedbreast.
 16. A system as in claim 15 in which said image displaycomprises a first graphical display displaying one or more of thepenetrating radiation images of the patient's breast for identificationof the region of interest within the patient's immobilized breast; ausers interface operatively associated with said first graphicaldisplay, far entering a selection by a user of a portion of at least oneof said displayed penetrating radiation images wherein said portion isassociated with said identified region of interest; and a secondgraphical display, separate from said first graphical display andlocated proximate to the patient's immobilized breast, for providingsubstantially real-time images responsive to said selection by saiduser, in connection with said first display, of said selected portion ofsaid patient's immobilized breast so that the user can monitor insertionof said medical device to said identified region of interest within saidpatient's immobilized breast using said second graphical display locatedproximate to said patient's immobilized breast.
 17. A system as in claim15 in which said second graphical display is movable relative to saidimmobilizer such that a user can locate said second graphical displayfor convenient viewing during insertion of said medical device into saididentified region of interest within said patient's immobilized breast.18. A system as in claim 15 in which said second graphical display isangularly moveable so that a user can adjust an angle of said graphicaldisplay for convenient viewing during insertion of said medical deviceto said identified region of interest within said patient's immobilizedbreast.
 19. A system as in claim 15 in which said ultrasound imagescomprises ultrasound transducers and a supporting structure forselectively positioning the transducers in acoustic coupling with theimmobilized breast, and including position indicators providinginformation regarding the spatial position of the transducers relativeto a frame of reference related to said penetrating radiation imagingand ultrasound imaging.